A378480 Products of 3 distinct prime numbers (or sphenics) that are deficient.

105, 110, 130, 154, 165, 170, 182, 190, 195, 230, 231, 238, 255, 266, 273, 285, 286, 290, 310, 322, 345, 357, 370, 374, 385, 399, 406, 410, 418, 429, 430, 434, 435, 442, 455, 465, 470, 483, 494, 506, 518, 530, 555, 561, 574, 590, 595, 598, 602, 609, 610, 615, 627, 638, 645, 646, 651, 658, 663, 665

Offset: 1

Author

Massimo Kofler, Nov 28 2024

Keywords

• nonn

Examples

			105 is a term because 105=3*5*7 is the product of three distinct primes and it is larger than the sum of its proper divisors (1+3+5+7+15+21+35=87).
110 is a term because 110=2*5*11 is the product of three distinct primes and it is larger than the sum of its proper divisors (1+2+5+10+11+22+55=106).
		

Crossrefs

Intersection of A005100 and A007304.

Programs

Mathematica

q[n_] := Module[{f = FactorInteger[n]}, f[[;; , 2]] == {1, 1, 1} && Times @@ (1 + 1/f[[;; , 1]]) < 2]; Select[Range[1000], q] (* Amiram Eldar, Nov 28 2024 *)